Valve for percussive tools.



F. M. SLATER.

VALVE FOR PEHCUSSIVE TOOLS APPLICATION man MAY25,1917'.

kg., Patented Dec. 31,1918;

2 SHEETS-SHEET l.

F. M. SLATER. VALVE FOR PERCUSSIVE TOOLS. APPLICATION FILED MAY`2'5`. I9l7.

mag-,$85.

2 SHEETS-SHEET 2.

Fg. 6 sa l Y INI/mmf? rivm l A ArroR/vfy L Patented Dec. 31,.)I918.

UNITED STATES PATENT FFICE.

FREI) M.`SLATER, F EASTON, PEN-NSYLVAIA,' ASSIGNOR TO INGERSOLL-RA-ND COM- PANY, .OF JERSEY CITY, .NEW JERSEY,'A QORPORATION OF NEW JERSEY.

VALVE FOR PERCUSSIVE TOOLS.

messes..

Specification of Letters Patent-- Patented Dec.'3]l, 1918.

T 0 all ywhom 'z't may concern.'

Be it known that L FRED M. SLATER, a

citizenof the United States, residingat Easton, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Valves for. Percussive Tools, of which the following is a specification. Y

rThis invention relates to iiuid operated percussive tools, and more particularly to tools of the type wherein the piston has two rearward pressure surfaces and vone forward pressure surface, one of the rearward pressure surfaces being subjected to constant pressure and the other vtwo surfaces vbeing subjected to intermittent pressure.

The objects ofthe [present invention are to provide a tool of Athis type in which the admission of`tluid'to the `intermittently sup.

plied forward and rearward surfaces of the piston is controlledfby a valve whereby the admission of tluid to the rearward surface is continued for a longer time during the forward stroke than duringthe rearwardstroke of the piston` an increase in power and efficiency being thus obtained; furtlier, to embrace within the valve controlling the admission of the Huid to the intermittently .supplied portions of the cylinder an exhaust valve controlling' the openingr and closing of auxiliary exhaust ports from the intermittently supplied portions of the cylinder; further, to operate said valve in one direction by fluid pressure admitted againstpne head of the valve through a piston controlled port and in the other direction by constant pressure against a part of the valve. With these and other objects in view, my invention consists in the features of con-- struction and operation set forth in the following` specification.

ln the drawings annexed hereto and forining a part of this specification, y

Figure 1 shows a cross sectional view of the entire tool;

Fig. 2, a section taken on the line Ill-II of Fin'. 1;

Fig. 3, a section taken on the line' III-III of Fig. 1; i

Fig. 4, a diagrammatic View of the tool" fthe piston being shown at the end of its forward stroke;

Fig. 5, a diagran'imatic Iview of the tool with the piston and valve in another4 position; and

Fig. 6. a slight modification shown diagraminatically.

As shown in the drawings, the toolcomprises a cylinder 1 having a forward bore 2 of large diameter and a rearward bo--e 3 of smaller diameter in which a differential piston 4 having a head 5 fitting the larger portion of the cylinder 2 and a shank portion G fitting the smaller portion of the cylinder 3 operates. Extending' forwardly gagring shank 7 having flutes 8 by means of which the drill chuck and drill 10 are r0 tated. The piston 4 is operated by Fluid pressure supplied to the tool through thehinl'et 11, which fluid pressure is distributed on either side of the piston head 5 by means of a val've 12 presently to be more fully described. The tool is provided with the 'usual rilcd bar 13. and ratchet 14, by means of which the piston and consequently the drill .from the head 5 of the piston Ltis a drill enis rotated, these, however, formingV no part of the present invention are shown only inV K outline. y

'lhesi'naller bore 3 of the cylinder 1 is continuously.in `direct communication with -thc inlet 11 and is therefore subjected to constant pressure which pressure is exerted against thc end of the piston shank 6. The motive fluid supplied to the larger bore 2 of the cylinder 1 is intern'rittently supplied to 'either end by means of ports 15 and 16 extending from the valve 12 to either endA of the lbore 2. The valve 12 which is clearly -shown in Figs. 2 and 3 will now he more fully described.

This valve 12 comprises two head portions of dierent diameters 17 and '18, respectively, connected by a neck or reduced .portion Extending vpractically throughout the ce: tralsection of the valve 12 is a hole 20y havingan opening out through the smaller head f1.8. .Extending from the end face of the larger head 17 to the central hole 2() is aleak' port 21, and extending from thev iu eonununication.with atmosphere through port Vlfl

vided with. a central constantly open exhaust port 23 opening' to atmosphere which port is uniro'fered by the head 'of the piston 4r at the end of the stroke oi: the piston in either direction. v

its the operation oi my tool will be more obvious from the diagrammatic views of, the tool in `Figs. i and it will be described in eonneetion with these figures. in Fig. Li, the piston i is shown at the forward end of its stroke, the valve 12 having been thrown to admit 'fluid to the forward end of the cylin- ,der bore 2 to retract the piston Fluid is admitted to the tool through the inlet pas- 'saire 11 and through passage 24. to the rear face of the shank against which a constant pressure is exerted. W hen the valve is -in the position shown Huid passes through the inlet 11 around the reduced portion 19 of the valve l2 to the 'passage 15 where it eX- erts pressure against the forward face of the piston head 5to force the piston rearwardly. As soon as the piston has moved rearwardly a portion ot'its stroke, the shank Got the piston fi covers the piston controlled port which is open oniv when the piston 4i vis in the forward portion ot its stroke. After the piston shank 6 has covered the port 25 the tluid within Isaid passage and in the valve chest pressing` against thev4 head 17 of the violve l2 leaks out hy means of the leak port 21 through the hole 2O and out through the auxiliary exhaustport 26 to atmosphere. .iijv the time the piston has approached its 'moet rearwardly position the pressure eX- erted against the head 17 has been .freatlv 'reduced so that the pressure emistambv eX- erted against the annulus between the reduced portion 19 and the head 17 is sutil eient to overeonie it whereupon the valve is toreo-d rearwardh.' to the position shown in Fig. 5.

l'eterring to Fig'. 5. it will be seen that the valve when in this position eloses the passage'i to the forward face of the piston head 5 and opens the passage 16 admitting luid to the rearward tace, thus iorcingr the pistou forward again. held open until the piston shank G uncovers the port 25 when the valve 12 is thrown to` its iiorward position as shown in Fig. 4,

when the ahove deseribed cyeie ot .events isA repeated.

The valve12 not onlvcontrols the admis- 'sion oi fluid tothe intermittently supplied portions oi' the cylinder-vas above described. but also operates as an auxiliary exhaust. valve in a manner `to be prisentiy described.

it will be noted that when the. valve 12 is ine iarg'e here 2 oi the cylinder 1 is pro,

The. passage 16 isl weones in the position shown in Ll. tluid is being prevent too great an air cushion forming' which would tend to shorten the stroke of the piston sland impair the eiiicieney of the tool. This auxiliaivvv exhaust is aecomplishe'd by means of the holes 22 bored through the head 17 ot the valve 12 which are in con'nnu'nieation with port 16 when the valve is in the position shown in this gure. It will thus he seen that the exhaust is continued until the valve is thrown to its opposite positionD which does not occur until the piston has almost reached the end of its stroke.

"With the valve in the position shown in Fig. 5. and while tiuid is being admitted to the rear of the bore 2, the Aexhaust takes place after the central exhaust has loten closed through the port 15 and past the smaller head 18 of the valve 12,'to the auxiliary exhaust 26.

in Fig-:.6 is shown a slight modification of the invention in which constant pressure is exerted against the rear face 27 of the piston head l28, pressure being admitted intermit- .teutly to the rear ot the piston shank 29 and the front face 30 ot the piston head 28 by means of the valve 12 through ports 31 and 32, respectively, in a manner similar to that shown in the form of the invention disclosed in Figs. 1 to 5. In this form of the invention an additional exhaust port is provided for the smaller bore 3 of the cylinder. The operation of the valve in this modification of the invention is in every Waysimilar to that in the other.

lt is to be understood that while the pres#l ent showing and deseription disclose only certain specific embodiments of the present invention. other forms and modifications are included within the spirit and scope thereof. as expressed in the appended Claims.

hat claim is: `1. A valve for percussive tools compris ing two head portions oi' different diameter.

neck portion connecting said head portions, an exhaust port extending from the cvlindrieal surface of the larger headporvtion to the central portion of the opposite end oi the valve, and a leak port extending from said larger head portion toA said exhaust passage.

2. .in a fiuid operated percussive tool, a cylinder, a piston therein having two rear pressure areas and one forward pressure area. a valve comprising' two head portions ot di'lorent diameters, aneok portion connecting' said head portions, the head portions oneach side of the neck portion controlling the opening and closing of communication between the ends of the cylinder and the fluid supply, an exhaust passage through said vvalve to exhaust fluid from one end of said cylinder, said valve having a` leak port intereepting said exhaust passage, said. valve being thrown in one direction by fluid pressure exerted interi'nittently against the larger of said heads and in the opposite direction by constant pressure against the anniilus formed by the larger head and neck of the valve.

3. In a fluid operated percussive tool, a

cylinder, a differential piston therein havv ing two rearward pressure areas and one forward pressure area, means for maintaining constant fluid pressure on one'rear ard f'ace of the piston, a differential valve for alternatively controlling the supply and ex- -haust from two of said pressure areas, said c vlinder provided wit ia` piston controlled port for intermittently supplying motive fluid from a constantly supplied portion of the cylinder to the larger end of the valve to move the valve inone direction.

4. ln a-flu-id. operated percussive tool. a c vlinder. a piston therein having a head and a shank portion, a differential valve for alternatively controlling the supply and exhaust from pressure areas of said piston' head, said cylinder provided with a piston controlled port t0 intermittently admit motive fluid against the larger head of the valve to move said ,valve in one direction. and means 'to exhaiist said motive fluid 'through said valve. i

5. ln a fluid operated pereussive tool. a cylinder, a piston ltherein, a valve, to control the supply and exhaust of motive fluid com prisinfr two head portions of different diameters, a neck portion coi'inectmgr said head portions. said cylinder provided with a piston controlled port to intermittently admit motive fluid agaii'ist the larger head of the valve to move the valve in one direction and :in exhaust passage through said valve to exhaust fluid from one end of' Said cylinder` said valve having a leak port for exhausting said intermittently supplied fluid.

f3. lin a fluid operated permissive tool, a

-eylindei', a piston therein, a valve comprising two head portions of different diameters, a neck connecting said head portions, the portions adjacent to the neck serving to open and elose communication between a fluid supply and the ends of said cylinder, an exhaust passage through the valve to .exhaust motive fluid from one end ofE said cylinder,

said valve being moved in one directit'ui by motive fluid pressure constantly exerted against the annulus formed by the larger head and the neck ot the valve, and piston cOntrolledmeans for intermittently supplying motive fluid pressure to the larger end of the valve to niove said valve in the opposite direction, said valve yhaving a leak port for exhausting said intermittently supplied inotive fluid from the larger end of the valve. l

i'. In a fluid operated percussive tool, a cylinder. a piston therein, a valve having heads of' different diameter adapted to be thrown in one direction by the pressure of motive fluid applied to the portion between the heads. piston controlled means for intermittently applying motive fluid to the larger end of' the valve to move said valve in tliemtlier direction, said valve haying a leak port for exhausting said pressiir vr said valve controlling ports for alternately supplying and exhausting the motive fluid from the opposite ends of the cylinders.

'8. ln a fluid operated pereussive tool, if. cylinder. a piston thereixrhaving two rear pressure areas and one forward pressure area, a valve comprising two head portions of different diameters. a neck portion connecting said head portions, the head portions on each side ofthe neck portion controlling the opening and closing of communication between the ends of the cylinder and the fluid supply,` an exhaust passage through said valve to exhaust fluid from one end-ot` said eylii'ii'ler, said valve having a leak port extending from the face, of' the larger head to the exhaust, said valve being thrown Iin one direction by fluid pressure exerted interinittentl y against the larger of said heads and in the opposite direction by constant pressure against the annulus formed by the larger head and neck of' the valve.

i). ln a fluid operated percussive tool, a

cylinder, a piston therein havingl a head 1 and a shank portion` a differential valve for alternatively controlling the'supply ai-id exhaust 'from pressure areas of said piston head, said cylinder provided with a piston controlled port to interniittently admit movtive fluid against the larger head of themunication between an auxiliary exhaust port in one end of' the cylinder and the atmosphere and said valve having al leak port Y intereepting said passage.

fl. A valve for perciissive tools comprisingtwo head portions, a neck portion connecting said head portions, said neck portion opening and closing communication loetween either end of the cylinder and the e having :i passage }i i'iiiir:,1iig an inerinibbeiit un bri-'mwen in auxiliary exhaust emi (if rh@ rfliiiiiicifr sind the fil*- iare iid said faire haring i iard; pori; ifii'iig; from the facu of on@ iieaifii@ @ha i'iiiv *for par@ iva-tools;`coiiipriswo izwiiiporioiifs of (iiieiienii dimiieter, irimi cmiiiefciing Suid head pob i M; naci: poiin opening :finzi sie iiiimiicaitiuii bait/W292i either @mi of thi; dri' and tix@ iiiici supply, said vain@ Hiring; :f:y passage dierehi'migii periiiitiiig wi 'iiiteriiiitent coii'imiinicutioii iii-tween an 'said miv-e i0 exhaust i of diffe-rant diameers, a naci; portion com meeting saisi head porioiis, the head portions on e ch side if ih@ neck porioii ycoiiroiiiiig5" the cipiiing and closing of ccmniimicziioii bsb'ween 'the @mis 0f the cyiimiei' imi 'iie {iui supply., :in exhausi; passage ti'irougii inici from one @mi (if said cyiini'lera said valve haring ziieak pari; extending from the face of the larger iwi-iii in the ezil'iaiisL'-, Said miv@ being? thrown in om direction bj; fiuifi pressure exerts@ iiiterniitentiy against the larger of said heads;

and in the oppcsite direction by Constant',

pressure against the aniiuhis formed byiis larger head and neck of the vaivehs the pressure on the large liead`faiis du@ to tha reduction in pressure of i'he motive finiti intermittently supplied :igaiiis said ,bami escaping through said leak port.

In'testimony Whereof,` i have heremitq sci, my hand.

FRED M. @LATER 

